Broadband penetration rates among residential customers are fast approaching 20% of all on-line subscribers and demand for high-speed Internet access is growing. Competition for these lucrative high-margin customers is fierce and also growing. Although asymmetric digital subscriber line (ADSL) is the primary choice of most customers for their broadband services, slow ADSL roll-outs by service providers and limitations of today's digital subscriber line access multiplexer (DSLAM) technology have left large gaps in the ADSL deployment strategies of many local telephone companies. These gaps are quickly being filled by cable operators eager to capture high-margin revenues that broadband service offerings attract, not to mention the growing opportunity for cable operators to offer bundled voice and data services and gain a toe-hold in the voice services market.
Two significant gaps in most local telephone companies ADSL service offerings are an inability to serve DAML (digitally added main line) customers and residential/small business customers that live beyond the 12,000 ft ADSL serving area. These two segments represent over 20% of the total ADSL market and neither segment can get ADSL service using traditional ADSL equipment.
DAMLs are devices that local telephone companies deploy to residences needing multiple plain old telephone service (POTS) lines, when there is a shortage of copper loops. For more than a decade, digital added main lines (DAMLs/AMLs) have provided carriers with a simple solution for copper pair relief of voice services. Although DAMLs provide multiple POTS lines over an existing copper pair, DAMLs do not support ADSL service delivery. Today, the two to three million customers that are currently served with DAML/AML devices are among the heaviest home users of telecommunication services. To further exacerbate this situation, recent studies show that nearly 75% of all multi-line residential customers are interested in ADSL-based service. With the majority of multi-line households desiring broadband services local telephone companies are not able to meet the needs of these premium customers. Currently, carriers are forced to not offer ADSL to this large segment of premium customers because carriers cannot justify the high cost of placing new cable to deliver ADSL to these customers. Many of these customers are looking to cable operators to meet their need for high-speed Internet access. The resulting situation has left many local telephone companies frustrated for they have a ready-made ADSL subscriber base but cannot satisfy the demand without enormous outside cable plant upgrades. Local telephone companies need a solution that will enable them to compete effectively with cable operators for this lucrative market segment.
The second major gap in most local telephone ADSL service deployments is the 20% of residential subscribers that live beyond 12,000 ft from a central office (CO) or remote Digital Loop Carrier (DLC) location. Poor loop quality and other technical limitations of Digital Subscriber Line Access Multiplexer (DSLAM) equipment installed by local telephone companies limits many asymmetric digital subscriber line (ADSL) deployments to 12,000 ft to 15,000 ft from a central office (CO) or digital loop carrier (DLC) remote. Some of the technical limitations of DSLAMS include:                DSLAMs/Remote DSLAMs are practical only to about 12,000 ft from a CO or DLC.        A DSLAM/Remote DSLAM is limited to offering only one voice circuit with every ADSL interface.        DSLAMs/Remote DSLAMs cannot serve multiple POTS lines and ADSL to a single home without a costly upgrade to a voice over a digital subscriber line—DSLAM, voice-gateway and locally powered integrated access device.        
Residential customers located beyond 12,000 ft of a typical 18,000 ft carrier serving area (CSA), however, comprise about 20 percent of the total ADSL market and are among the heaviest users of telecommunication services. Cable operators are aggressively targeting these “long reach” customers with cable modems that offer significantly higher bandwidth than ADSL service at the same distances. Local telephone companies need a solution that will enable them to compete effectively with cable operators for delivery of high-speed Internet access to these hard to reach customers.
Unfortunately for many local telephone companies, DAML-based and long-reach customers are beginning to purchase data service from cable operators. Regrettably, that lost business may be difficult to recover. Even more unwelcome is the fact that the cable companies will, sooner or later, be offering voice services.
For the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for improvements in the provision of asymmetric digital subscriber line services.